The parish church is dedicated to Saint Sebastian the Martyr. It is thought to have been erected in the first half of the 16th century as a votive offering, when the town flourished again following several plagues and famines. With the new church comes a change in patron saint and parish seat, moving from the small church of St. Saturninus, until then a parish church, to St. Sebastian. The early layout of the church was erected in Catalan Gothic forms, of which only the lower part of the bell tower and the chapel of the baptismal font located at its base remain today. Thanks to a bequest in his will in 1709, the bell tower was elevated with a domed octagonal body. In the second half of the 18th century, the parish underwent a radical transformation that gave it its present Baroque appearance. The interior is rich in Baroque and Rococo furnishings, carved by Ligurian and Sardinian artists in the second half of the 18th century. The chancel is bordered by the marble balustrade; in the center rises the high altar executed between 1769 and 1801; it preserves the 17th-century antependium with the figures of St. Sebastian, St. Saturninus and St. Lussorio. The 1771 pulpit towers in the center of the nave. Singular is the sculpture of a lion placed at its feet that the elder Ussanesi call “su cani de sa trona” (the dog of the pulpit).
